show: show all namespaces in "work" view This commit addresses a number of deficiencies in `hg show work`'s output: * Failure to render tags (it just wasn't implemented) * Failure to render names associated with non-built-in namespaces (e.g. remotenames) * Color names were hardcoded instead of coming from the canonical source in the namespace This change has the intended effect of rendering tags and extra namespaces. It solves an immediate need at Mozilla of having names from a custom namespace printed, which is blocking us from switching from a custom `hg wip` revset/template combo to `hg show work`. Note that the order of branches and bookmarks changes. This is because bookmarks are registered before branches in namespaces.py. We may want to register them last, after tags and branches. Or we may want to added a weighted field to the namespace to control display order. Something to think about. I'm not a big fan of the complexity in the templating layer. There is a lot of code to basically filter out the special case of branch=='default' and tag=='tip'. Ideally, we would iterate over a data structure that had irrelevant/unwanted names pre-filtered. However, I wasn't sure how to best implement this. We probably want {namespaces} to emit everything (its current behavior). I was toying with the following: * {namespacesnondefaults} variation that filtered values * A filter function that operated on {namespaces} (I wasn't sure how to implement this since the filtering layer would see a "hybrid" instance as opposed to something that was definitely an iterable of namespaces.) * A namespaces(...) function where you could specify which values to return. I like this the most. But it really wants named arguments to control filtering and we only support named arguments on revsets, not templates. I figure perfect is the enemy of good and we can refine templating support for namespaces in the future. At least now we have a concrete example of a use case.

tests: add more tests for names rendering in `hg show work` This demonstrates some missing features. This will also help verify that a subsequent change has the intended effect.

namespaces: record and expose whether namespace is built-in Currently, the templating layer tends to treat each namespace as a one-off, with explicit usage of {bookmarks}, {tags}, {branch}, etc instead of using {namespaces}. It would be really useful if we could iterate over namespaces and operate on them generically. However, some consumers may wish to differentiate namespaces by whether they are built-in to core Mercurial or provided by extensions. Expected use cases include ignoring non-built-in namespaces or emitting a generic label for non-built-in namespaces. This commit introduces an attribute on namespace instances that says whether the namespace is "built-in" and then exposes this to the templating layer. As part of this, we implement a reusable extension for defining custom names on each changeset for testing. A second consumer will be introduced in a subsequent commit.

templatekw: expose color name in {namespaces} entries Templates make use of a "log.<namespace>" label. The <namespace> value here differs from the actual namespace name in that the namespace itself is plural but the label/color value is singular. Expose the color name to the templating layer so log.* labels can be emitted for {namespaces}. As part of this, we refactored the logic to eliminate a gnarly comprehension. We store color names in their own dict because the lookup can occur in tight loops and we shouldn't have to go to repo.names[ns] multiple times for every changeset.

show: construct changeset templater during dispatch Previously, we constructed a formatter from a specific template topic. Then from show() we reached into the internals of the formatter to resolve a template string to be used to construct a changeset templater. A downside to this approach was it limited us to having the entire template defined in a single entry in the map file. You couldn't reference other entries in the map file and this would lead to long templates and redundancy in the map file. This commit teaches @showview how to instantiate a changeset templater so we can construct a templater with full access to the map file. To prove it works, we've split "showwork" into components.

cmdutil: use named arguments for changeset_templater.__init__ This will make the API more extensible and easier to use.

bundle: inline applybundle1() We have now gotten rid of all but one caller, so let's inline it there.

bundle: make applybundle() delegate v1 bundles to applybundle1()

bundle: transpose transaction scope with bundle type switch This moves the transaction with-statements outside of the per-bundle-version switches, so the next patch will be a little simpler.

unbundle: move BundleUnknownFeatureError exception handling out This just moves the BundleUnknownFeatureError exception handling one level up so we collect the bundle2.applybundle{,1}() calls together. applybundle1() will never throw the exception, so it should have no functional consequence.